Is A1's 24F recorded at 24fps or 23.98fps? at DVinfo.net

Cal Bickford · March 16th, 2008, 07:55 AM

I'm very confused about this whole topic. I've read conflicting information such as, "most video is recorded at 23.98fps", "A1 records at 23.98fps", "24f is true 24fps" etc etc. Can anyone help?

Rob Stoner · March 16th, 2008, 11:59 AM

my understanding is that the a1 records its 24fps as 23.98fps. i believe that what people are referring to when they say that "24f is true 24fps" they are referring to a 3:2:2:3 pulldown that occurs on some cameras.

Cal Bickford · March 16th, 2008, 12:37 PM

Ok so I've been mulling this over and I wonder if I'm not missing something obvious - does a 23.98fps apply only to interlaced footage? I know this could be a very stupid question but I'm just not grasping how .98 of a progressive frame can be displayed...

Rob Stoner · March 16th, 2008, 03:12 PM

the 23.98 applies to both interlaced as well as progressive footage. it has to do with the refresh rates of tv's.

Cal Bickford · March 18th, 2008, 09:53 AM

interestingly enough I just got a reply from canon saying that the A1 records at 29.97 fps in 24p mode - which makes sense considering the 2:3 pulldown I guess. I've posted a question about proper capture presets here on the fcp forum:

http://www.dvinfo.net/conf/showthread.php?t=117252

Kevin Shahinian · September 8th, 2008, 03:42 PM

The A1 has an option in-menu to record 24f in either 2:3 or 2:3:3:2.

Just wondering if there is any advantage to removing the pulldown if the output will be an NTSC DVD (29.97 fps)? Does editing in "true" 24P yield a better DVD? If so, what pulldown software was used? Thanks.

Tom Roper · September 9th, 2008, 08:41 PM

Quote:

Originally Posted by Kevin Shahinian

The A1 has an option in-menu to record 24f in either 2:3 or 2:3:3:2.

Just wondering if there is any advantage to removing the pulldown if the output will be an NTSC DVD (29.97 fps)? Does editing in "true" 24P yield a better DVD? If so, what pulldown software was used? Thanks.

Makes no difference in my judgment for HD. The only time it would, is 24p output from a Blu-ray player to a monitor that accepts native 1080p24 input.

Editing in "true" 24P would make no difference as long as you are not rendering.

You can use the free utility "dgpulldown.exe" to quickly strip the pulldown flags from the Canon 24f (29.97 with repeat flags), or add them back in, without rendering.

Bill Busby · September 10th, 2008, 05:26 AM

Quote:

Originally Posted by Kevin Shahinian

The A1 has an option in-menu to record 24f in either 2:3 or 2:3:3:2.

Just wondering if there is any advantage to removing the pulldown if the output will be an NTSC DVD (29.97 fps)? Does editing in "true" 24P yield a better DVD? If so, what pulldown software was used? Thanks.

Actually (and someone correct me if I'm missing something here), I believe those pulldown options pertain to the component out (and/or HD/SDI on the G1). Through firewire though, 24f is 24 distinct frames.

Jean-Philippe Archibald · September 10th, 2008, 05:58 AM

This is what I though too. In HDV, firewire is 24p if the 24f mode was used. From component out you get the 2:3 pulldown. The choice of 2:3 or 2:3:3:2 is only used when using 24p in SD mode.

Bill Busby · September 10th, 2008, 06:41 AM

I was curious myself & had later found the info on page 40 of the pdf manual. Seems as though only 2:3 is added to component out in HDV, & as you said... the choice of 2:3 or 2:3:3:2 is only used when using 24p in SD mode.

Bill Pryor · September 10th, 2008, 08:59 AM

This is correct, via firewire, HDV shot at 24f is 24 frames per second. No pulldown.

Tom Roper · September 10th, 2008, 11:19 AM

Sorry, but output from the firewire also has 3:2 repeat flags added.

To restate, 24 encoded progressive frames yes, but with 3:2 repeat flags added.

Your NLE may ignore them, but they are there. There is no change to the filesize.

If you (or your NLE) don't remove them, the native stream authored to Blu-ray will playback 1440x1080, 29.97 not 23.98.

You may not notice this since your NLE is doing a render, but understand the native stream itself can be authored to Blu-ray using an mpeg utility without rendering, and it will be 29.97 with 23.98 progressive frames embedded within. It will not playback as 24fps from a Blu-ray disk unless an NLE subsequently renders it to 24p, or you strip the repeat flags from the native file with the aforementioned pulldown removal tool.

Download the freeware dgpulldown.exe utility and read the readme file. Then run the program on a native XH-A1 24f capture.

March 16th, 2008, 07:55 AM	#1
Cal Bickford Regular Crew Join Date: Jan 2007 Location: Austin, TX Posts: 157	Is A1's 24F recorded at 24fps or 23.98fps? I'm very confused about this whole topic. I've read conflicting information such as, "most video is recorded at 23.98fps", "A1 records at 23.98fps", "24f is true 24fps" etc etc. Can anyone help?

September 8th, 2008, 03:42 PM	#6
Kevin Shahinian Regular Crew Join Date: Aug 2008 Location: Southern California Posts: 116	24f: to pulldown or not to pulldown... The A1 has an option in-menu to record 24f in either 2:3 or 2:3:3:2. Just wondering if there is any advantage to removing the pulldown if the output will be an NTSC DVD (29.97 fps)? Does editing in "true" 24P yield a better DVD? If so, what pulldown software was used? Thanks. __________________ www.PacificPictures.net

September 10th, 2008, 05:58 AM	#9
Jean-Philippe Archibald Trustee Join Date: Sep 2003 Location: Saguenay, Québec, Canada Posts: 1,051	This is what I though too. In HDV, firewire is 24p if the 24f mode was used. From component out you get the 2:3 pulldown. The choice of 2:3 or 2:3:3:2 is only used when using 24p in SD mode. __________________ Jean-Philippe Archibald http://www.jparchibald.com - http://www.vimeo.com/jparchib

March 16th, 2008, 11:59 AM	#2
Rob Stoner Regular Crew Join Date: Sep 2007 Location: Milwaukee, Wisconsin Posts: 50	my understanding is that the a1 records its 24fps as 23.98fps. i believe that what people are referring to when they say that "24f is true 24fps" they are referring to a 3:2:2:3 pulldown that occurs on some cameras.

March 16th, 2008, 12:37 PM	#3
Cal Bickford Regular Crew Join Date: Jan 2007 Location: Austin, TX Posts: 157	Ok so I've been mulling this over and I wonder if I'm not missing something obvious - does a 23.98fps apply only to interlaced footage? I know this could be a very stupid question but I'm just not grasping how .98 of a progressive frame can be displayed...

March 16th, 2008, 03:12 PM	#4
Rob Stoner Regular Crew Join Date: Sep 2007 Location: Milwaukee, Wisconsin Posts: 50	the 23.98 applies to both interlaced as well as progressive footage. it has to do with the refresh rates of tv's.

March 18th, 2008, 09:53 AM	#5
Cal Bickford Regular Crew Join Date: Jan 2007 Location: Austin, TX Posts: 157	interestingly enough I just got a reply from canon saying that the A1 records at 29.97 fps in 24p mode - which makes sense considering the 2:3 pulldown I guess. I've posted a question about proper capture presets here on the fcp forum: http://www.dvinfo.net/conf/showthread.php?t=117252

September 10th, 2008, 06:41 AM	#10
Bill Busby Major Player Join Date: Dec 2006 Location: Los Angeles, CA Posts: 959	I was curious myself & had later found the info on page 40 of the pdf manual. Seems as though only 2:3 is added to component out in HDV, & as you said... the choice of 2:3 or 2:3:3:2 is only used when using 24p in SD mode.

September 10th, 2008, 08:59 AM	#11
Bill Pryor Contributor Join Date: Jan 2003 Location: Kansas City, MO Posts: 4,449	This is correct, via firewire, HDV shot at 24f is 24 frames per second. No pulldown.

September 10th, 2008, 11:19 AM	#12
Tom Roper Trustee Join Date: Jun 2004 Location: Denver, Colorado Posts: 1,891	Sorry, but output from the firewire also has 3:2 repeat flags added. To restate, 24 encoded progressive frames yes, but with 3:2 repeat flags added. Your NLE may ignore them, but they are there. There is no change to the filesize. If you (or your NLE) don't remove them, the native stream authored to Blu-ray will playback 1440x1080, 29.97 not 23.98. You may not notice this since your NLE is doing a render, but understand the native stream itself can be authored to Blu-ray using an mpeg utility without rendering, and it will be 29.97 with 23.98 progressive frames embedded within. It will not playback as 24fps from a Blu-ray disk unless an NLE subsequently renders it to 24p, or you strip the repeat flags from the native file with the aforementioned pulldown removal tool. Download the freeware dgpulldown.exe utility and read the readme file. Then run the program on a native XH-A1 24f capture.